FORMATION OF DEFECTS IN ZINC SELENIDE CRYSTALS GROWN FROM MELT UNDER ARGON PRESSURE

The formation of macroscopic defects in ZnSe crystals is described. Crystals were grown by the Bridgman technique at the lowering rate of a crucible of 0.8-10.1 mm/h under an argon pressure of 100 kg/cm2. The formation of the assembly of rod-like low angle grain boundaries was dependent upon the angle θ between the growth axis and the (111) twin plane normal. For 75° < θ < 90° the rod-like low angle grain boundaries occurred and for θ < 75° crystals free of the boundaries grew at the lowering rates used in our experiments. The formation of voids was dependent on the lowering rate of the crucible. Many crystals free of these defects were obtained in the growth range 0.8-2.5 mm/h. © 1978.